----CustomDatePicker.java----
import java.util.Map;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.DatePicker;



public class CustomDatePicker extends DatePicker {
   	private Paint mPaint;

	
    public CustomDatePicker(Context arg0, AttributeSet arg1, Map arg2) {
    	super(arg0, arg1, arg2);
    	this.setBackgroundColor(0xFFFFFFFF);
    	mPaint = new Paint();
     }

    @Override protected void onDraw(Canvas canvas) {
    	super.onDraw(canvas);
    	Paint paint = mPaint;
    	paint.setColor(Color.BLUE);
    	paint.setStrokeCap(Paint.Cap.SQUARE);
    	paint.setStrokeWidth(10);
    	canvas.drawRect(1f, 1f, 40f, 40f, paint); 
    
    }
} 

---------ShowData.java----
import android.app.Activity;
import android.os.Bundle;



public class ShowData extends Activity {
	private CustomDatePicker dp;
	
    @Override
    public void onCreate(Bundle icicle) {
    	super.onCreate(icicle);
    	setContentView(R.layout.show_data);
    	
    	dp = (CustomDatePicker) this.findViewById(R.id.super_date);    	
    	dp.init(2008, 3, 20, 1, null);
    	
    }


    
}